Sprecher
Beschreibung
Latest Maastrichtian ecosystems remain central to debates surrounding dinosaurian diversity and ecological resilience prior to the Cretaceous–Palaeogene (K–Pg) mass extinction. However, relatively few studies have examined how floral turnover influenced trophic interactions and ecosystem structure immediately prior to the Chicxulub impact. Here, we reconstruct ecosystem-scale trophic networks from the Hell Creek Formation using the R package cheddar and an integrated palaeofloral and vertebrate dataset spanning the final ~2 million years of the Cretaceous. For the first time, explicit taxon-level trophic links between plants, herbivores, and higher consumers were reconstructed across the Hell Creek ecosystem using a functional trait-based framework incorporating feeding and growth height, browsing selectivity, inferred oral processing capabilities, along with mechanical toughness. Floral data were synthesized from both megafloral and palynological records across all recognised Hell Creek megafloral zones, reducing preservational bias and allowing reconstruction of temporal changes in vegetation structure and composition.
Our results indicate increasing abundance of mechanically tougher and woodier shrubs through the middle and upper Hell Creek succession, suggesting greater structural complexity within the herb–shrub layer. These changes in the most intensely browsed upon plant strata correspond with restructuring of herbivore guilds and shifts in niche partitioning. Broad-spectrum megaherbivores such as ceratopsids and Edmontosaurus annectens remained comparatively resilient, whereas intermediate selective browsers, including nodosaurids and some pachycephalosaurids, appear disproportionately affected by increasing niche compression and resource overlap. These results suggest latest Maastrichtian ecosystems were undergoing ecological restructuring prior to the K–Pg boundary rather than uniform ecological decline.